Search form

Search form

The Pennsylvania Department of Transportation is using fly ash from power plants and blast-furnace slag from steel mills to replace a portion of the cement used to make concrete for roads, sidewalks and bridges. In fact, new state standards being developed for concrete are so strict that suppliers cannot meet them without using fly ash or slag, observers say. They also say the ash and slag make concrete less vulnerable to damage caused by water and salt.

Related Summaries

California-based Watershed Materials is working to develop concrete blocks made with no cement. The company has already created its Watershed Block, using only 5% portland cement, supplementing it with other material such as slag, fly ash, rice hull ash and silica fume. It's now at work to develop a press that would further reduce the amount of cement needed. The ideal press would apply "compressive forces so great as to actually lithify mineral grains, turning loose sediment into stone."

The New Dali Museum in St. Petersburg, Fla., which contains the famous works of Salvador Dali, was designed to maximize resistance against the elements and achieve energy sustainability. The museum was built using glass that can withstand a Category 3 hurricane and thick concrete walls that can weather a Category 5 hurricane. The concrete used to build the museum contains a mixture of fly ash and slag, and the building utilizes a solar hot water dehumidification system.

The New Dali Museum in St. Petersburg, Fla., which contains the famous works of Salvador Dali, was designed to maximize resistance against the elements and achieve energy sustainability. The museum was built using glass that can withstand a Category 3 hurricane and thick concrete walls that can weather a Category 5 hurricane. The concrete used to build the museum contains a mixture of fly ash and slag, and the building utilizes a solar hot water dehumidification system.

Fly ash, a byproduct of burning coal, could help repair concrete buildings, bridges and roads, researchers say. The researchers note that using the fly ash to coat concrete could prolong the life of those structures -- at about half the cost of today's coating materials. Tests have shown that the coating protected concrete from deterioration when it was exposed to the acids present in air pollution.

The Pennsylvania Department of Transportation is using fly ash from power plants and blast-furnace slag from steel mills to replace a portion of the cement used to make concrete for roads, sidewalks and bridges. In fact, new state standards being developed for concrete are so strict that suppliers cannot meet them without using fly ash or slag, observers say. They also say the ash and slag make concrete less vulnerable to damage caused by water and salt.